The present disclosure relates to a method for producing an integrated micromechanical fluid sensor component, to an integrated micromechanical fluid sensor component and to a method for detecting a fluid by means of an integrated micromechanical fluid sensor component. The fluid may, in particular, be a gas or a gas mixture. During the detection, a molecular concentration of the fluid, or in the fluid, or a type of fluid may in particular be determinable.
Optical spectroscopy for the detection of constituents (analytes) of a fluid, for instance of a gas mixture, is based on the interaction of the analytes with photons. A structure consisting of a light emission device, for instance an LED or a laser diode, a detector, for instance a photodiode or a thermopile, and an optical measurement path is conventionally used for the measurement. The optical measurement path extends at least partially through the fluid to be analyzed, or the fluid to be analyzed is introduced into the measurement path. This may, for example, be done actively by forming a flow or passively by allowing convection or diffusion. Signals of the detector are read out in order to be able to draw conclusions about, for instance, a type of fluid or a molecular concentration. In this case, use is made of the fact that the emitted light is partially absorbed by the fluid to be analyzed and/or the analyte.
WO 2005/026705 A1 describes a gas detection method and a gas detection apparatus. The gas detector apparatus comprises a surface emitter, VCSEL, a test chamber and a light sensor. The light sensor detects light rays emitted by the surface emitter, which have passed through a gas to be detected in the test chamber. By means of connected electronics, signals generated by the light sensor are evaluated.
In so-called intracavity laser absorption spectroscopy, ICLAS, use is made of the fact that light makes a very large number of passes through an optical resonator. Since the sensitivity of the sensors depends on the optical path length in the medium, an extremely high sensitivity can be achieved with ICLAS methods.